Multiple stage ejector in refrigeration system



2 sheets-sheet 1 fizz 01 F. WHITNEY MULTIPLE STAGE EJECTOR INREFRIGERATION SYSTEM Filed Nov. 19, 1948 11.7.1. hwnrl' rm Sept. 4, 19512 Sheets-Sheet 2 jizuzzar L. F. WHITNEY MULTIPLE STAGE EJECTOR INREFRIGERATION SYSTEM Filed NOV. 19, 1948 Sept. 4, 1951 the top of drum50 is a spill-over duct 55, the

lower part of which provides a trap 56 connected to a mercury return 51which is connected wit the boiler I.

When sludge accumulates in the cooler II, it

forms a mud-like deposit on the lower walls of" the cooler and since thecooler is provided with downwardly sloping walls, this heavy, mud-likedeposit can drain into the drum 50. Since the drum 50 is connected tothe low-pressure portion of the system and is in'a relatively Warmlocation, the more volatile element of the heavy sludge, i. e.,the'aqueous refrigerant, is evaporated and drawn into the first stagemixing chamber through the duct, 3,-while the mercury residueflows intothe line 52 and thence into the spill-over 55 to the mercury return 51.Since the drum 50 extends a substantial distance below the spill-overconnection into the line 55, any sludge in the lower part of the drum issubjected to a substantial liquid head which results in a tendency tosqueeze refrigerant out of the sludge so that the mercury may coalesce.

The 'Y 28 which connects the drains and 21 communicates with a smalldrum or chamber 60 to which the lower end of the inclined pipe 40 isalso connected, while an upwardly inclined duct 61 extends from thischamber 66 to a chamber constituting a part of the purger assembly 63.The chamber 64 receives non-condensable gases through the pipe 30 and adrop tube 85 of restricted internal diameter extends downwardlytherefrom. Globules ofcondensed mercury spilling over from the duct BIentrain bodies of the non-condensable gases in the tube 65, compressingthe gases as they move downwardly through the tube. The lower end of thetube 65 is im- Ine'rsed in a body of mercury in the well 51, the uppersurface of this liquid propellant being exposed to atmosphere. A returnduct' 6-9 is circumposed about the tube 65 and is connected to themercury-returnpipe 51, there being a very small pressure-equalizing ventbetween the upper part ofthe duct 69 and chamber 64. A deflector 68prevents gas from rising into the duct 69 from the lower end of the droptube 65. The arrangement of the spill-over connection between the tubeSI and chamber 60 determines the level of the mercury in the trapdefined by the lower parts of the ducts 34 and 22. The condensed mercuryreceived from the drains I4 and 21 passes into the chamber 60 and fromthe latter may pass to the spill-over connection, thus being received bythe purger. From the purger the mercury flows from the pipe 51 back tothe boiler I, the height of the mercury in the pipes 51 and 69 beingsufficient to balance the boiler pressure. V

During normal operation of the system the trap defined by the pipes 5iand 40 is constantly receiving condensed mercury from the drains I4 and21, and the spill-overconnection between pipe BI and chamber 64definitely limits the height of mercury in the pipe 21. Thus, a mercurycolumn of'constant height is automatically maintained in the leg fil' ofthe trap while the total static pressure in this leg of the trap is 26,1939, to which reference may be had for a 4 provided by the mercurycolumn plus the condenser pressure thereabove. This static pressure isbalanced in the opposite leg of the trap by the mercury in the tube 40below its connection with the duct 34, and by the liquid columns in therespective branches 34 and 42 of this leg, as well as thepressures abovethese respective columns. The liquid heads in the branches 34 and ,42are provided by bodies of condensed mercury and aqueous reirigerant, asexplained more fully in Patent No. 2,174,300 granted to me Septembermore complete description of the operation of the system.

Inaccordance with the present invention, the

first and second stage aspirators and their associated parts constitutea unit which comprises an elongate housing I00 of generally ovoid crosssection having a closed rear end IN and a front end I02 formed withvertically spaced openings which receive the first and second stageaspirators I04 and I05, respectively. The floor or'bot-f tom wall I03slopes slightly from the front -to-; ward the rear so that condensateaccumulating therein runs toward the rear wall. The aspirator I04 may beof the samegeneral design as shown in my prior Patent No. 1,756,802granted April 29, 1930, comprising an elongate funnel III] the enlargedend III of which'isin spaced axial alignment with anozzle II2 connectedwith the branch 5 of the riser 5 The space betweenthe nozzle and funnelconstitutes a mixing chamber surrounded by a perforate casing II4 whichis disposed within a dome-like closure or cap II5 which is formed withan en larged opening to receive the" vapor duct '8; Throughout the majorportion of its length the funnel I l0.is provided with heat-dissipatingus and a jacket II8 surrounds the funnel, this jacket having a pluralityof longitudinally extending fin 9 along its lower wall portion 5 and anopening I20 formed in its upper wall outside the housing I00. Oppositethe discharge end .of thefunnel H0 is a deflector plate .I2I carried bythe end wall IOI of the housing. The lower wall of the housing iprovided with a drain opening I24 which is connected with the line I4.

The aspirator I05 is generally similar to the aspirator I04 andcomprises an elongate funnel I25 having an intake end I26 in spacedalignment with a nozzle I28 connected tothe branch line 5 of riser 5. Asleeve I30 extends about the space or mixing chamber between the nozzleand funnel, and this sleeve is formed with spaced perforations orinletsso as to provide a corn: munication between the interior of the'housing'and the mixing chamber. A jacket or casing I32 surrounds the funnel andat approximately the 'center of the jacket is a partition I34 (Fig; 2)which divides its interior into two sections I35 and I36.

A series of baflles I38 fit about the outlet end of the funnel withinthe chamber or section I35 and the lower ends of alternate baflies arecut so as to provide egmental openings I40 (Fig'i l) to permitcondensate to run toward the closed end I42 of the jacket. The closedend of this jacket carries a deflector plate I44 and is formed with adrain opening to which the line 2"I,is connected. The upper end of thechamber I35 between partition I34, and the baffles is provided with anopening to which the vapor; line 20 is connected, and the lower end of,the chamber provided with a discharge opening to which the drain pipe 21is connected.

The intake end of the funnel within the section I36 carrie a series ofheat-dissipating fins I45 and the upper part of this chamber is providedwith an enlarged opening directly connected with a similar opening inthe floor of the jacket I I8 by a short duct I46. The interiors of thejacket H8 and the chamber I36 are filled with alcohol or other similarliquid which receives heat from the gases passing through the funnelsand transmits the same by way of a pipe I50 which connects the opening Iin the jacket H8 with a condenser I5I located in a hot water supply tankT.

The tank T is provided with a connection I55 leading to the condenserI5I by mean of which the alcohol circuit may be initially evacuated sothat the alcohol therein may vaporize at a relatively low temperature(around 176 F.) when the temperature of the water around the condenser I5| is 170 F. The tank T is also provided with an inlet line I55 forreceiving incoming water from the supply main, and a hot water supplyline I51 is connected with the upper part of the tank, as in my priorPatent No. 2,174,302 granted September 26, 1939, to which reference maybe had for a more complete description of this part of the system.

In operation, mercury vapor discharged from the nozzle 5 aspirates watervapor through the duct 8 and carries it through the funnel IIO,compressing it and discharging the compressed hot vapor into theinterior of the housing I00. A substantial amount of heat is absorbed bythe alcohol in the jacket H8, and any condensed mercury falls to thebottom of the housing I00 and eventually passes into the drain pipe I 4.The compressed Water vapor and any uncondensed mercury is drawn into theecond stage aspirator and carried through the funnel I which results infurther compressing the water vapor which, after passing about thebaffies I38, is discharged into the duct 29. The condensed mercuryaccumulating in the bottom of the chamber I flows through the openings Iinto the drain '21. Heat from the second stage aspirator is absorbed bythe alcohol in the section I36 and circulates upwardly through thejacket H8 and duct I into the condenser I5I where alcohol vapors arecondensed and thu give up their heat to the water in the tank T, as ismore fully described in my above-mentioned Patent No. 2,174,302.

While I have shown and described one desirable embodiment of theinvention, it is to be understood that this disclosure is for thepurpose of illustration and that various change and modifications may bemade without departing from the spirit and cope of the invention as setforth in the appended claims.

I claim:

1. In a refrigeration system of the type having a refrigerant fluidcircuit including a vapor duct and a condenser duct, a propellant fluidcircuit including a pressure line and a return line, and a cooling fluidcircuit, a multiple stage ejector unit comprising a housing of elongatecross-section, a first stage ejector connected with said vapor duct andwith said pressure line and extending within th upper part of saidhousing, a second stage ejector connected with said. pressure line andextending within the lower part of said housing, jackets about theejectors having a connection with said cooling fluid circuit, the firststage ejector discharging into the interior of said housing and thesecond stage ejector having a vapor inlet communicating with theinterior of said housing so as to receive vapors discharged by the firststage ejector, a connection between the outlet of the second stageejector and said condenser duct, and return means from the outlet ofsaid second stage ejector and the interior of said housing to saidreturn line.

2. In a refrigeration system of the type having a refrigerant fluidcircuit including a vapor duct and a condenser duct, a propellant fluidcircuit including a pressure line and a return line, a multiple stageejector unit comprising a housing, a first stage ejector connected withsaid vapor duct and with said pressure line and extending within onepart of said housing, a second stage ejector connected with saidpressure line and extending within another part of said housing, acasing surrounding the discharge end portion of said second stageejector, the first stage ejector discharging into the interior of saidhousing and the second stage ejector having a vapor inlet communicatingwith the interior of said housing so as to receive vapors discharged bythe first stage ejector, a connection between said casing and saidcondenser duct, and return means from said casing and the interior ofsaid housing to said return line.

3. In a refrigeration system of the type having a refrigerant fluidcircuit including a vapor duct and a condenser duct, and a propellantfluid circuit including a pressure line and a return line, a multiplestage ejector unit comprising a housing, a first stage ejector connectedwith said vapor duct and with said pressure line and extending withinone part of said housing, a deflector plate carried by said housingopposite the discharge end of said ejector, a second stage ejectorconnected with said pressure line and extending within another part ofsaid housing, the first stage ejector discharging into the interior ofsaid housing and the second stage ejector having a vapor inletcommunicating with the interior of said housing so as to receive vaporsdischarged by the first stage ejector, a connection between the outletof the second stage ejector and said condenser duct, a second deflectorplate disposed opposite the discharge end of said second ejector, andreturn means from the outlet of said second stage ejector and theinterior of said housing to said return line.

LYMAN F. WHITNEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENT Number Name Date 1,343,922 Ljungstrom June 22, 19201,521,729 Suczek Jan, 6, 1925 1,546,641 Fothergili et a1. July 21, 19252,174,302 Whitney Sept. 26, 1939

